Importing User Controls into WSS 3.0
This is insane.
I have a user control test.ascx. It is a valid user control, containing nothing but a string of text to display. In an ASPX page derived from the Sharepoint base page type, it displays perfectly happily as a web part.
I put a copy in the sharepoint root, and try to upload the following web part file for it (and yes, I've done all the SafeControl, etc settings for it.
<?xml version="1.0" encoding="utf-8" ?>
<webParts>
<webPart xmlns="http://schemas.microsoft.com/WebPart/v3">
<metaData>
<type src="~/Test.ascx" />
<importErrorMessage>
Error: Cannot import this Web Part.</importErrorMessage>
</metaData>
<data>
<properties>
<property name="Title" type="string">
TEST</property>
<property name="Description" type="string">
TEST</property>
</properties>
</data>
</webPart>
</webParts>
And when I try to preview the webpart I get: The element is required. Add this element to the Web Part file (.webpart), and then try to import the Web Part. at Microsoft.SharePoint.WebPartPages.WebPartImporter.CreateWebPart(Boolean
When I put it in a virtual directory and change the webpart file to this:
<?xml version="1.0" encoding="utf-8" ?>
<webParts>
<webPart xmlns="http://schemas.microsoft.com/WebPart/v3">
<metaData>
<type src="~/_customcontrols/Test.ascx" />
<importErrorMessage>
Error: Cannot import this Web Part.</importErrorMessage>
</metaData>
<data>
<properties>
<property name="Title" type="string">
TEST</property>
<property name="Description" type="string">
TEST</property>
</properties>
</data>
</webPart>
</webParts>
I now get: Exception of type 'Microsoft.SharePoint.WebPartPages.WebPartPageUserException' was thrown. at Microsoft.SharePoint.WebPartPages.WebPartImporter.CreateWebPart
Now, both files validate, and point to a real location, etc, etc, but the second file matches what I really want to do, and the error message is completely meaningless. There are about 14 places in CreateWebPart that exception might be thrown, but they should all have a message to display.
I run SharePoint in full trust to remove any security issues, still the same problem. I log / write info from a static constructor, never happens. This tells me it is something to do with the webpart file. But how do I find out?